Shops, restaurants and schools will be closed across most of Italy on Monday, with PM Mario Draghi warning of a "new wave" of the coronavirus outbreak.
For three days over Easter, 3-5 April, there will be a total shutdown.
Italy, which one year ago imposed one of the first national lockdowns, is once again struggling to contain the rapid spread of infections.
The country has reported more than 100,000 Covid-related deaths, Europe's second-highest tally after the UK.
Italy's vaccination campaign has been hit by delays, as has been seen elsewhere in the European Union.
Anglo-Swedish drug company AstraZeneca has announced a further shortfall in the amount of its vaccine it can supply to the European Union, blaming export restrictions imposed by some countries. It did not elaborate.
In January, it announced a large cut in the 100m doses it had originally expected to deliver to the EU by March, sparking a public spat with European Commission.
Last week the government in Rome blocked the export of 250,000 doses of the Oxford-AstraZeneca vaccine to Australia to address shortfalls of vaccines.